Modern personal computers (PCs) make extensive use of graphical user interfaces (GUIs). GUIs enable multiple data sets and applications to be simultaneously displayed and manipulated by means of "windows" imaged on the PC's display and a pointing device for controlling the size and placement of the windows. Windows may be partially or completely overlapping, reduced to iconic representation, or expanded to fill the entire display. A pervasive example of the above-described type of GUI is the Microsoft Windows software program.
A problem commonly experienced by GUI users results during attempts to display more than one large window on a single computer display at one time, as a typical display is too small to display two or more windows without substantial overlap therebetween. A solution to this problem has been to develop monitors that are larger and have a substantially greater display area than typical monitors. Such monitors are capable of displaying several large windows simultaneously; however, they generally require more desk space than most users are willing or able to spare.
Dual monitor systems are also known and employed to enable the display of more than one large window at a time. In such dual monitor systems, a secondary display controller and associated display are interfaced to the computer in parallel with the primary display controller and associated display. GUI software is commercially available which regards the dual displays as a single correspondingly larger virtual display system, so that cursor manipulations and data entry move from screen to screen in a natural manner. A single data window may be configured to span both screens, although the physical gap in the middle of the larger virtual display, due to the fact that computer monitors cannot be positioned sufficiently close together, is distracting to most users. More typically, one display will be used for displaying active data entry, while the other will be used for displaying static reference data, for example, help screens. Dual display systems suffer the same drawback as large display systems with respect to the amount of space required to use them.
Because the allocation of additional desk space by a user to his or her computer is usually unacceptable or impossible, despite the prospect of improved productivity that may be achieved therewith, computers incorporating larger monitors or dual display systems are not in widespread use. Therefore, what is needed is an apparatus for providing a computer with a larger display area that does not require additional desk space and that minimizes the physical gap inherent in a dual display system.